This invention relates to a remote control wireless keyboard musical instrument, and more particularly to a musical system including a portable transmitter having keys, a remote receiver, and a musical device coupled to the receiver for generating musical sounds when corresonding keys of the transmitter are actuated.
In recent years much work has been done in the field of electronic musical instruments, with the object of (i) creating new musical instruments capable of producing unique musical sounds, and (ii) improving the operation or simplifying the construction of existing musical instruments.
There is a need, however, for a musical system which enables a performer to move freely about while playing a musical composition. With the advent of increased interaction between performers and their audiences, there has been a greater tendency for many performers to leave the stage at times and to move through the audience, speaking to individual persons in the audience and playing musical selections for them. This trend has been accelerated by the advent of wireless microphones, which eliminate the restriction of movement caused by the microphone cable between a performer and his remote amplifier unit.
This method of entertainment, in which a performer moves through an audience and plays musical selections as he moves about, has heretofore been limited to the use of musical devices which were relatively light in weight and sufficiently small in bulk to be portable. Typical devices used by performers moving about in their audiences might be accordians, quitars, violins, small wind instruments, etc.
Because of the obvious size and weight limitations of the musical equipment which a performer can carry as he moves through an audience, it is not possible for such a performer to play relatively bulky and heavy musical devices which produce more impressive, desirable, or preferred sounds, such as pianos or organs. Thus there is a need for a musical system whereby a performer may carry a relatively light weight, relatively small remote control unit as he moves through an audience or otherwise moves about, and thereby control the operation of a remote musical device, e.g. a keyboard musical instrument such as a piano or organ. Preferably, such a system should employ a wireless communication link between the portable control unit and the remote portions thereof, to eliminate the need for a cumbersome and restrictive cable connection between the same.
Although systems have been devised for the automatic or remote control of keyboard musical instruments by means of wire data links between the control source and the musical device being played, there has been little or no attention given by practitioners of the electronic musical instrument art to the wireless control of musical devices in general and keyboard musical devices such as pianos and organs in particular.
For example, the automatic playing of pianos has been a well developed art for over fifty years, the most well known examples of this art being player pianos controlled by perforated paper rolls. In the player piano art there is also known an accessory unit, such as that of U.S. Pat. No. 1,109,554, which can be detachably secured to a piano above the keys thereof, to automatically depress predetermined keys, by means of electrically controlled solenoid devices. U.S. Pat. No. 883,252 shows a bracket arrangement for detachably mounting a piano action, i.e. a playing device to be disposed immediately above the piano keyboard, with facilities for adjusting the bracket position to align the piano action with the underlying piano keyboard keys. These patents are hereby incorporated into this application by reference thereto, to the extent they disclose features applicable to embodiments of the invention herein described.
U.S. Pat. No. 3,709,085 shows a teaching device in which a remote keyboard is provided which is coupled by wires to an elongated housing disposed above the keyboard of a keyboard musical instrument. The housing includes a plurality of solenoids, one solenoid being positioned above each key of the musical instrument to be played, so that in one mode of operation a teacher can play the remote keyboard and the corresponding keys of the keyboard musical device will be depressed by the remotely controlled solenoids mounted within the elongated housing positioned over the instrument keyboard. See in particular FIG. 15 of this patent and the corresponding description at column 6, lines 38 to 65. To the extent it is applicable to embodiments of the invention herein described, the disclosure of this patent is incorporated herein by reference thereto.
U.S. Pat. No. 3,388,206 shows a guitar which includes a number of switches mounted by its fingerboard for controlling a remote organ through wires.
U.S. Pat. No. 3,610,802 shows an accordian-organ in which the organ electronics and speaker are located in a remote unit connected to the accordian-organ control units by wires.
U.S. Pat. No. 3,825,666 shows a system in which a guitar includes the equivalent of a wireless microphone, i.e. the audio output of the guitar is transduced and radiated to a remote receiver, the output of which drives a speaker. Only the audio signal generated by the guitar is transmitted. There is no transmission of data corresonding to discrete keys, functions, or desired musical sounds.
The use of multiplex techniques and computer storage and retrieval techniques in conjunction with electronic organs is well known in the art. For example, U.S. Pat. No. 3,905,267 shows an arrangement for utilizing multiplex techniques to transform the key depressions of an organ (corresonding to a musical composition being played on the organ) into a digital code. The code is then recorded on a tape recorder, for later playback through a decoder which drives solenoids to depress the organ keys to replay the original composition.
U.S. Pat. Nos. 3,915,047 and 3,926,088 describe arrangements in which an organ is electronically coupled to a computer by wires and the organs keys being depressed during a performance are converted into digital data which is stored or analyzed by the computer. U.S. Pat. No. 3,926,088 referred to above also shows a computer scheme for displaying the music in musical notation as it is played by the performer.
U.S. Pat. No. 3,968,716 shows a keyboard instrument employing multiplex transmission by wires from the keyboard to remote tone generators (multiplex is employed to reduce the number of wires needed), and wireless transmission of the audio information from the tone generators to remote speakers. Like U.S. Pat. No. 3,825,666, this system does not employ wireless transmission of data corresponding to particular keys or musical sounds to be reproduced.
Multiplex schemes for multiplexing the information as to which keys are being depressed during a performance on an organ are also described in U.S. Pat. Nos. 3,875,842, 3,899,951 and 3,916,750, none of which employ wireless transmission of data.
Of the three patents mentioned in the preceding paragraph, U.S. Pat. No. 3,899,951 employs an asynchronous organ key scanning arrangement which is similar in principle to the portable transmitter key scanning arrangement employed in the embodiment of the instant invention hereafter described; however, as will become apparent upon studying the detailed description of said embodiment which follows, there are differences in implementation between said patent and the aforementioned embodiment.
Like the multiplex schemes mentioned above in connection with prior art patents, the invention herein described utilizes multiplex techniques to convert the key depressions of a keyboard made during a performance into a digital code. However, in addition to the many other differences between the instant invention and prior art, an important feature of the invention is the transmission of the digital code to a remote receiving unit by wireless rather than through wires, as is done in the prior art multiplexing schemes referred to above.
Although at first blush it might seem obvious to substitute wireless transmission for transmission through wires simply by modulating a suitable carrier wave with a digital information to be transmitted, and demodulating the same at a receiver, this does not prove to be the case when a practical system is to be constructed for transmitting data corresponding to musical notes or sounds, or other musical functions.
The reason for this difference in design considerations between conventional transmission of multiplexed musical data through wires, and wireless transmission of the same, is twofold.
First, while DC signals and levels can be readily transmitted through wires, DC transmission is inherently nonexistent in wireless transmission, which by its nature permits only of the radiation of AC signals. This is an important limitation, since in order to accurately decode a digital signal of the type normally employed, it is necessary to establish a DC reference level for the decoding equipment. This absence of DC transmission capability is accompanied by the need for the receiver to have a very good low frequency response, so as to minimize the DC reference problem referred to above; unfortunately, such low frequency response can only be obtained at the expense of additional complexity and cost of the receiver, sometimes also at the expense of poor recovery characteristics from high level noise impulses, which may "paralyse" the receiver momentarily.
Another serious problem encountered in wireless transmission of musical data and not normally present to a significant degree in systems employing transmission by wires, is susceptibility to noise in general, and impulse noise in particular. One might conclude that such noise considerations should not be a problem because of the relatively short distances involved in transmission between a performer while moving about his audience, and a remote receiver which might be located on or near the stage. However, it has been discovered in actual field trails that noise interference is a factor which is particularly significant in remote control wireless music systems of the type to which the instant invention is directed. This is so for two principal reasons.
One reason that noise considerations are significant in spite of the relatively short transmission distances involved, is the limitation on the power that may be transmitted. For a wireless system to be practicable on a marketing basis, it is essential that no special communications licenses be required. Under such conditions, the Federal Communications Commission (FCC) has prescribed by regulation that the radiated power must not exceed 100 milliwatts if compliance with its many regulations and licensing requirements is to be avoided. Therefore this power limitation is unavoidable as a practical matter.
The effectiveness of utilization of this radiated transmitter power (100 milliwatts maximum) is further limited by antenna inefficiencies. Because of practical limitations on the size of the transmitting antenna which a performer can carry, and the requirement that the antenna be omnidirectional (so that it will radiate to the remote receiver independently of turning movements of the performer as he moves through the audience) the antenna efficiency cannot be maximized, resulting in an effective loss of transmission power. Similarly, it is rarely practicable to provide the receiver unit with a sufficiently large antenna to provide maximized reception efficiency.
Because of these power and efficiency limitation, noise sources present in a theater or night club establishment which might otherwise not be troublesome, become a matter for concern, and their effect on the system must be minimized. Such noise surces may include air conditioning units, motors, fluorescent lighting, blenders utilized by bartenders, kitchen equipment, etc. Cars and trucks passing the outside of the establishment may also radiate troublesome impulse noise.
Another reason why noise considerations are particularly significant in a wireless remote control music system of the type herein described is the inherent sensitivity of such a system to noise, in the sense that a noise effect which might be insignificant in another type of data transmission system, may be very disruptive in such a music system.
For example, where a performer is moving about with a portable transmitter having a plurality of keys while playing a composition thereon, the system herein described provides for transmission of a code identifying the depressed keys, so that the remote receiver unit can cause a musical device depressions as a piano or organ to reproduce the key depressios of the portable transmitter to play the desired musical composition. It is not difficult to see that if a dissonant note appears in the midst of the composition at a key far above or below the key of the composition being played, the effect would be highly disruptive. In such a musical system, even a single wrong note of this type caused by a noise impulse could destroy the effect the performer is seeking to achieve. Obviously, the appearance of any undesired note (caused by a noise impulse) during a pause in the performance would likewise by very disruptive.
Thus it is clear that in a wireless remote control music system of the type herein described, a high level of noise immunity is highly desirable.
Accordingly, an object of the present invention is to provide a practical remote control wireless keyboard musical instrument.
Another object of the invention is to provide such an instrument having a high level of noise immunity.
Still another object of the invention is to provide such an instrument in which the required low frequency response characteristics of the receiver unit are alleviated.